Key Questions - Respiratory Care

Vikki Knowles, BSc, DipNP, RGN, is respiratory clinical lead, south west locality, Surrey PCT, and trainer, Education for Health, Guildford.

How do I differentiate between asthma and Chronic obstructive pulmonary disease (COPD)?

Both asthma and COPD share symptoms of airflow obstruction which may present as wheeze, breathlessness or cough. Detailed history-taking helps differentiate between the two conditions although both conditions can co-exist in the same patient.

Consider a diagnosis of COPD in any patient over 35 years who is a smoker or ex-smoker, complaining of breathlessness on exertion, chronic cough, sputum production, winter bronchitis and wheeze with no clinical features of asthma. Asthma should be considered if the onset is early in life, symptoms present at night or early morning, vary from day to day, are associated with allergic disease and there is a family history of the condition. To confirm diagnosis, lung function will need to be measured objectively as asthma will show largely reversible airflow obstruction, unlike COPD which is defined as predominantly irreversible airflow limitation.

How should I manage an exacerbation of COPD?

COPD is a progressive disease with symptoms of breathlessness, sputum production and cough. Exacerbations have the biggest impact on disease progression and are the main cause of hospitalisation and death. Exacerbations can be either mucoid or infective and be triggered by environmental irritants, viruses or bacterial infection.
Management should focus on symptom control and assessment of severity. Breathlessness can be managed by increasing bronchodilator therapy and considering a change in delivery system, for example, large volume spacer. Antibiotics should be prescribed when sputum shows increased volume and persistent discoloration from normal, with reduction in exercise tolerance. Oral steroids are indicated when there is a poor response to increased bronchodilators. Severe symptoms such as increased confusion, cyanosis or unresponsive breathlessness indicate the need for hospital admission.

Should GPs prescribe oxygen without prior assessment?

No - oxygen has clear indications for its administration and use. It can be used to treat hypoxaemia and has been shown to reduce the work of breathing and reduce myocardial workload. However, patients who need oxygen often cannot tolerate it and vice versa.

There are clear indications for the use of long-term oxygen therapy in patients with COPD and it is the only treatment known to improve the prognosis in hypoxic patients with severe forms of the condition. Arterial blood gases should be checked on two occasions three weeks apart when stable to determine suitability. Prescription of short-burst oxygen for palliation of symptoms is less clear-cut and patients need careful assessment to ensure a safe response to treatment.

When should I use inhaled corticosteroids in COPD?

Inhaled corticosteroids are indicated for patients with an FEV1 less than or equal to 50% predicted, who are having two or more exacerbations requiring treatment with antibiotics or oral corticosteroids per year. Inhaled steroids should be given in combination with long-acting bronchodilators within licence for COPD. Inhaled corticosteroids reduce risk of exacerbation and reduce the rate of oral steroid courses given during exacerbations.

How safe are inhaled corticosteroids?

Inhaled therapy is delivered directly to the lungs and consequently the dose required to achieve an anti-inflammatory effect is much lower than with an oral dose. Very little of the dose will be absorbed into the body from the lungs, minimising any risk of side-effects. The main side-effects associated with inhaled therapy are oral thrush and hoarse voice but these can be minimised by using a spacer device and rinsing the mouth after use. High-dose inhaled steroids may carry a slight increased risk of systemic effects; however the risk/benefit ratio favours the use of high-dose steroids in severe uncontrolled asthma.

Further reading

Bellamy, D., Booker, R. (2004) Chronic Obstructive Pulmonary Disease in Primary Care (3rd ed). London: Class Publishing Ltd.

Price, D. et al (2004) Churchill’s In Clinical Practice Series: COPD and Asthma. Oxford: Churchill Livingstone.

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